diff options
| -rw-r--r-- | ChangeLog | 17 | ||||
| -rw-r--r-- | INSTALL | 6 | ||||
| -rw-r--r-- | Makeconfig | 7 | ||||
| -rw-r--r-- | Makerules | 9 | ||||
| -rw-r--r-- | iconvdata/Makefile | 5 | ||||
| -rw-r--r-- | manual/install.texi | 6 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/alpha/localplt.data | 2 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/i386/localplt.data | 2 | ||||
| -rw-r--r-- | sysdeps/x86_64/localplt.data | 2 |
9 files changed, 47 insertions, 9 deletions
diff --git a/ChangeLog b/ChangeLog index a587b9a2a5..bed3bd1e5c 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,20 @@ +2017-03-02 Florian Weimer <fweimer@redhat.com> + + [BZ #21015] + * manual/install.texi (Configuring and compiling): Document + --enable-bind-now. + * Makeconfig [bind-now] (LDFLAGS-lib.so): Set. + (build-shlib-helper): Use $(LDFLAGS-lib.so). + (format.lds): Likewise. + [bind-now] (LDFLAGS-c.so): Remove. + * sysdeps/x86_64/localplt.data (libm.so): matherr relocation can + be R_X86_64_GLOB_DAT. + * sysdeps/unix/sysv/linux/i386/localplt.data (libm.so): matherr + relocation can be R_386_GLOB_DAT. + * sysdeps/unix/sysv/linux/alpha/localplt.data (libm.so): matherr + relocaiton can be R_ALPHA_GLOB_DAT. + * iconvdata/Makefile [bind-now] (LDFLAGS.so): Add -Wl,-z,now. + 2017-03-01 Zack Weinberg <zackw@panix.com> * include/libc-pointer-arith.h: New file. Define diff --git a/INSTALL b/INSTALL index 3b3fd121b2..e77cb2d4e2 100644 --- a/INSTALL +++ b/INSTALL @@ -146,6 +146,12 @@ will be used, and CFLAGS sets optimization options for the compiler. of routines called directly from assembler are excluded from this protection. +'--enable-bind-now' + Disable lazy binding for installed shared objects. This provides + additional security hardening because it enables full RELRO and a + read-only global offset table (GOT), at the cost of slightly + increased program load times. + '--enable-pt_chown' The file 'pt_chown' is a helper binary for 'grantpt' (*note Pseudo-Terminals: Allocation.) that is installed setuid root to fix diff --git a/Makeconfig b/Makeconfig index 97a15b569e..1c815113b9 100644 --- a/Makeconfig +++ b/Makeconfig @@ -386,6 +386,13 @@ LDFLAGS.so += $(hashstyle-LDFLAGS) LDFLAGS-rtld += $(hashstyle-LDFLAGS) endif +# If lazy relocations are disabled, add the -z now flag. Use +# LDFLAGS-lib.so instead of LDFLAGS.so, to avoid adding the flag to +# test modules. +ifeq ($(bind-now),yes) +LDFLAGS-lib.so += -Wl,-z,now +endif + # Command to run after every final link (executable or shared object). # This is invoked with $(call after-link,...), so it should operate on # the file $1. This can be set to do some sort of post-processing on diff --git a/Makerules b/Makerules index e9194e54cf..7f0eef8096 100644 --- a/Makerules +++ b/Makerules @@ -588,7 +588,7 @@ $(LINK.o) -shared -static-libgcc -Wl,-O1 $(sysdep-LDFLAGS) \ $(extra-B-$(@F:lib%.so=%).so) -B$(csu-objpfx) \ $(extra-B-$(@F:lib%.so=%).so) $(load-map-file) \ -Wl,-soname=lib$(libprefix)$(@F:lib%.so=%).so$($(@F)-version) \ - $(LDFLAGS.so) $(LDFLAGS-$(@F:lib%.so=%).so) \ + $(LDFLAGS.so) $(LDFLAGS-lib.so) $(LDFLAGS-$(@F:lib%.so=%).so) \ -L$(subst :, -L,$(rpath-link)) -Wl,-rpath-link=$(rpath-link) endef @@ -686,10 +686,6 @@ LDFLAGS-c.so = -nostdlib -nostartfiles LDLIBS-c.so += $(libc.so-gnulib) # Give libc.so an entry point and make it directly runnable itself. LDFLAGS-c.so += -e __libc_main -# If lazy relocation is disabled add the -z now flag. -ifeq ($(bind-now),yes) -LDFLAGS-c.so += -Wl,-z,now -endif # Pre-link the objects of libc_pic.a so that we can locally resolve # COMMON symbols before we link against ld.so. This is because ld.so # contains some of libc_pic.a already, which will prevent the COMMONs @@ -1104,7 +1100,8 @@ $(common-objpfx)format.lds: $(..)scripts/output-format.sed \ ifneq (unknown,$(output-format)) echo > $@.new 'OUTPUT_FORMAT($(output-format))' else - $(LINK.o) -shared $(sysdep-LDFLAGS) $(rtld-LDFLAGS) $(LDFLAGS.so) \ + $(LINK.o) -shared $(sysdep-LDFLAGS) $(rtld-LDFLAGS) \ + $(LDFLAGS.so) $(LDFLAGS-lib.so) \ -x c /dev/null -o $@.so -Wl,--verbose -v 2>&1 \ | sed -n -f $< > $@.new test -s $@.new diff --git a/iconvdata/Makefile b/iconvdata/Makefile index 04157b25c5..e4845871f5 100644 --- a/iconvdata/Makefile +++ b/iconvdata/Makefile @@ -63,6 +63,11 @@ modules := ISO8859-1 ISO8859-2 ISO8859-3 ISO8859-4 ISO8859-5 \ MAC-CENTRALEUROPE KOI8-RU ISO8859-9E \ CP770 CP771 CP772 CP773 CP774 +# If lazy binding is disabled, use BIND_NOW for the gconv modules. +ifeq ($(bind-now),yes) +LDFLAGS.so += -Wl,-z,now +endif + modules.so := $(addsuffix .so, $(modules)) ifeq (yes,$(build-shared)) diff --git a/manual/install.texi b/manual/install.texi index 266add8ba9..3398cfab02 100644 --- a/manual/install.texi +++ b/manual/install.texi @@ -175,6 +175,12 @@ options to detect stack overruns. Only the dynamic linker and a small number of routines called directly from assembler are excluded from this protection. +@item --enable-bind-now +Disable lazy binding for installed shared objects. This provides +additional security hardening because it enables full RELRO and a +read-only global offset table (GOT), at the cost of slightly increased +program load times. + @pindex pt_chown @findex grantpt @item --enable-pt_chown diff --git a/sysdeps/unix/sysv/linux/alpha/localplt.data b/sysdeps/unix/sysv/linux/alpha/localplt.data index cca17f1e34..1f0e3b494e 100644 --- a/sysdeps/unix/sysv/linux/alpha/localplt.data +++ b/sysdeps/unix/sysv/linux/alpha/localplt.data @@ -20,7 +20,7 @@ libc.so: free + RELA R_ALPHA_GLOB_DAT libc.so: malloc + RELA R_ALPHA_GLOB_DAT libc.so: memalign + RELA R_ALPHA_GLOB_DAT libc.so: realloc + RELA R_ALPHA_GLOB_DAT -libm.so: matherr +libm.so: matherr + RELA R_ALPHA_GLOB_DAT # We used to offer inline functions that used this, so it must be exported. # Ought to reorg things such that carg isn't thus forced to use a plt. libm.so: __atan2 diff --git a/sysdeps/unix/sysv/linux/i386/localplt.data b/sysdeps/unix/sysv/linux/i386/localplt.data index 2c2584956d..8ea4333846 100644 --- a/sysdeps/unix/sysv/linux/i386/localplt.data +++ b/sysdeps/unix/sysv/linux/i386/localplt.data @@ -6,7 +6,7 @@ libc.so: free + REL R_386_GLOB_DAT libc.so: malloc + REL R_386_GLOB_DAT libc.so: memalign + REL R_386_GLOB_DAT libc.so: realloc + REL R_386_GLOB_DAT -libm.so: matherr +libm.so: matherr + REL R_386_GLOB_DAT # The main malloc is interposed into the dynamic linker, for # allocations after the initial link (when dlopen is used). ld.so: malloc + REL R_386_GLOB_DAT diff --git a/sysdeps/x86_64/localplt.data b/sysdeps/x86_64/localplt.data index 014a9f4554..a1840cff31 100644 --- a/sysdeps/x86_64/localplt.data +++ b/sysdeps/x86_64/localplt.data @@ -8,7 +8,7 @@ libc.so: free + RELA R_X86_64_GLOB_DAT libc.so: malloc + RELA R_X86_64_GLOB_DAT libc.so: memalign + RELA R_X86_64_GLOB_DAT libc.so: realloc + RELA R_X86_64_GLOB_DAT -libm.so: matherr +libm.so: matherr + RELA R_X86_64_GLOB_DAT # The main malloc is interposed into the dynamic linker, for # allocations after the initial link (when dlopen is used). ld.so: malloc + RELA R_X86_64_GLOB_DAT |